Properties of PEN

Youngs modulus (kpsi) (machine direction (MD) 1 mil film) 

Property Test Method Units PEN Polyimide Polyetherimide Poly(ethylene terephthalate) film Polypropylene sulfide) 

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The performance properties of PEN present opportunities for replacement of rayon or polyamide in carcass construction. The use of PEN cord in these applications is currently being evaluated in both Asia and Europe. PEN has demonstrated acceptable flexural fatigue equivalent to polyethylene terephthalate (PET) and rayon. It has equivalent toughness to rayon, which is important for sidewall impact resistance. PEN s superior mechanical properties also afford opportunities to use less fiber in carcass construction enabling production of lighter-weight, more fuel-efficient tires. 

Although the superior properties of PEN have been known for many years, the unavailability of the naphthalate monomer has delayed the development of commercial markets, until relatively recently (1995) when the Amoco Chemical Company offered high purity naphthalene-2,6-dimethyl dicarboxylate (NDC) in amounts of up to 60 million pounds per year. This diester is produced by a five-step synthetic route, starting from the readily available compounds, o-xylene and 1,4-butadiene [3], Prior to this, the NDC diester was obtained by extraction of 2,6-dimethylnaphthalene (DMN) from petroleum streams, where it was present in relatively low abundance. Oxidation of DMN to crude 2,6-naphthalene dixcarboxylic (NDA) is conducted by a similar process to that used for conversion of p-xylcnc to purified terephthalic acid (TA), crude NDA is esterified with methanol, and is then distilled to yield high purity NDC. Other companies (e.g. the Mitsubishi Gas Chemical Company) followed Amoco s introduction with lesser amounts of NDC. Teijin [4] has manufactured PEN for many years for its own captive uses in films. 

Figure 9.3 Star diagram illustrating the improved properties of PEN when compared to PET PEN, black PET, white. From manufacturer s literature published by BP Chemicals and reproduced with permission... 

Figure 10.4 Star diagram showing comparison of the properties of PEN (-------) and PET (.)...

Table 10.1 Comparison of the properties of PEN with other commercial films... 

A comparison of the chemical resistant properties of PEN with PET is presented in Table 10.2. PEN shows a higher resistance to most chemicals than PET [19]. 

PEN is considered to be a high-performance polyester material. The advantageous properties of PEN are derived from its chemical structure which contains both... 

PEN has lower gas permeation coefficients than PET for carbon dioxide, oxygen and moisture for both film types. Although the gas-barrier properties of PEN are similar to those of poly(vinyl dichloride), it is not affected by moisture in the environment. Both oriented and unoriented PEN films restrict gas diffusion more... 

PEN him is like PET film, but superior in various properties, and is finding wide applicahon for magnehc tapes. Weick and Bhushan have compared the dynamic mechanical properties and wear/abrasion properties of PEN- and PET-based magnehc tapes. The PEN tapes have better dimensional stability, elastic moduli and coating thickness. They also have higher storage moduli... 

Flotation properties of pen [land ite are not well understood notability is in between chalcopyriie and pyrrhotite Naturally flolable since Mo S is sob, it can coat other minarals and thus enhance gengne dotation Quartz is the gangee Tor other minerals it can be floated easily wilh amines during the flotation of minerals sodium silicate can be used to depress quartz... 

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